Universal hands free key and lock system and method

ABSTRACT

Methods and systems are provided for a universal key that enables a user to have access to any type of secured portal, both physical and electronic, in a wireless, hands-free, distance-independent manner without requiring contact or line of sight access between the key and the secured portal. The universal key is not distance-dependent, and each secured portal can be provided with its own prescribed activation range, if desired. Some portals may be provided with long range activation, such as 50 feet, while other portals may be provided with short range activation of a few feet or less. The type of portal being secured and the range of activation may be selected by the user and is not limited by the universal key. In addition, the universal key will provide access to the secured portals in a hands-free fashion so that the user need not push any buttons or take any other action in order to obtain access to the portal. The user need only carry the universal key somewhere on their person in order to access the portal.

FIELD OF THE INVENTION

This invention relates to an access control system and in particular toan access control system in which multiple locks may be programmed toaccept the same universal key, so that the possessor of the universalkey is able to open the locks using a single key.

BACKGROUND OF THE INVENTION

Most people carry numerous keys to allow them to open doors to theirautomobile, house, office, garage and vacation home. New keys areconstantly being added into this collection as new locks are put intoservice and old keys are replaced when locks are changed. As a result,most key rings are bulky and heavy from their large number of keys.Often, finding the right key to open a lock is not an easy task,especially if the lock is located in a poorly lit area. Moreover, when aperson is using both arms to carry a load, setting down at least part ofthe load to free a hand to find the right key to unlock a door is bothtime consuming and difficult.

Accordingly, a need exists for a simplified key and lock system whichmakes it possible for a user to easily open any lock without having tocarry separate keys for different locks and which allows the user toopen any lock hands free (i.e., without having to touch a key orequivalent).

SUMMARY OF THE INVENTION

In accordance with this invention, methods and systems are provided fora universal key that enables a user to have access to any type ofsecured portal, both physical and electronic, in a wireless, hands-free,distance-independent manner without requiring contact or line of sightaccess between the key and the secured portal. The universal key is notdistance-dependent, and each secured portal can be provided with its ownprescribed activation range, if desired. Some portals may be providedwith long range activation, such as 50 feet, while other portals may beprovided with short range activation of a few feet or less. The type ofportal being secured and the range of activation may be selected by theuser and is not limited by the universal key. In addition, the universalkey will provide access to the secured portals in a hands-free fashionso that the user need not push any buttons or take any other action inorder to obtain access to the portal. The user need only carry theuniversal key somewhere on their person in order to access the portal.

In accordance with this invention, methods and systems are providedwhich allow a single universal key system to be used to open a pluralityof different locks. A hands-free, universal key that wirelessly andomnidirectionally transmits an ID code to open a plurality of differentlocks is provided. This single universal key can replace the largenumber of different keys that a person typically carries, includingmechanical tumbler-type keys, mag cards, automobile “keyless entry”transmitters, garage door openers, and the like. Because the systemallows hands free opening of locks, the system allows the user toquickly and easily pass through otherwise locked doors without settingdown loads or searching through pockets or purses for keys.

In accordance with an embodiment of the present invention, a universalkey carried on a user transmits wirelessly (e.g., an RF signal) a uniquecode to a reader coupled to a mechanism to activate a lock. Each lock tobe activated by the universal key is equipped with a reader whichreceives the code sent by the universal key. When the unique codetransmitted by the universal key (“ID code”) matches a correspondingcode in the reader, the reader recognizes the code and opens the lock.

In one embodiment, the reader is sensitive to its distance from theuniversal key. For example, for a garage door, the reader is capable ofdetecting the transmitted signal when the universal key is a selecteddistance (e.g., 100 feet), from the lock associated with the garagedoor. Accordingly, the reader will detect the transmitted signal whenthe universal key comes within the selected distance of and traveling ina direction towards the reader. The reader will then cause an actuatorto unlock the garage door, opening the garage door in response torecognizing the code carried by the RF signal. On the other hand, thereader associated with the lock on a door to a house will not recognizethe code on the RF signal unless the universal key is much closer to thedoor. For example, such distance could be three (3) feet or less fromthe reader associated with the lock on the door. The reader associatedwith the door lock would then detect and recognize the transmitted codeand cause the door to unlock.

In another embodiment of the invention, the reader in the lock issensitive to the direction from which the code is transmitted by theuniversal key, so that the code will only be detected by the readerassociated with the lock in the door when the user carrying theuniversal key is outside the door but not when the user is inside thedoor. This prevents the door from being inadvertently unlocked when theuser carrying the universal key passes close to the inside of the door.In addition, the lock may be configured to automatically unlock when thedoor is approached from the outside and will automatically lock when theuser walks away from the door on the outside and travels beyond thereceiver read range.

In one embodiment, the reader associated with a lock can be programmedto recognize a number of different ID codes, thereby allowing differentpeople to open the lock. In one embodiment, the system is capable ofrecognizing 10 billion unique ID codes. The reader can also beprogrammed to not allow the lock to be opened unless multiple ID codesare received simultaneously (i.e., two or more universal keys are inproximity of the receiver at the same time). This gives an enhancedsecurity option should it be required by the user.

In another embodiment of the invention, the reader is located in anautomobile and thereby allows the user to open the driver's door whenthe universal key carried by the user comes within a selected distanceof the driver's door. A typical distance would be five (5) to ten (10)feet, although other distances can also be selected if desired. Again,the reader is sensitive to the transmitted ID code only when theuniversal key carried by a user is within the selected distance from thereader associated with the lock. As with the door application above, thereader associated with the driver side door may be configured such thatthe ID code is not received or is disregarded when the driver carryingthe universal key is located inside the vehicle. The doors may beprogrammed to be automatically locked when the gearshift is put in drivewith the motor running. The universal key may continue to communicatewith readers outside the car, such as a reader associated with a garagedoor opener. When the driver exits the car, the reader associated withthe driver side door starts to pick up the signal from the universal keyand when the universal key gets beyond read range, the car door willautomatically lock.

In another embodiment, a warning system is provided in the door lock,the universal key, or both. The warning system notifies the user thatthe battery powering the respective circuitry is getting low, therebyprompting the user to replace the battery before the battery fails. Theuniversal key may also have a small supplemental battery for sounding analarm when the primary battery should be replaced.

In accordance with one embodiment of this invention, should the batteryfail, an ordinary key can be used to open the door. In one embodiment, akey can also be used to unlock the door even while the battery isadequate to power the motor associated with the lock, but the universalkey eliminates the need to carry an extra key for general usage.

The advantages that may be achieved by various embodiments of theinvention are numerous. For example, the user does not have to carry acollection of electronic or traditional keys, to remember numerouspasswords or personal identification numbers (PINs), or to rememberwhich opens which lock. These systems may save time by allowing the userto open a lock hands free as the user approaches the lock, rather thanwaiting until the user has reached the lock. It is also unnecessary forthe user to set down parcels, reach into his or her pocket orpocketbook, remove the key ring, find the right key, insert the key inthe lock and finally unlock the door. Instead, the user is able toautomatically unlock the lock as the user comes within the range inwhich the lock is capable of receiving the ID code from the universalkey. It is not necessary to put down groceries, a baby, or anything elsethe user may be carrying. When the door is pushed completely closed fromthe inside (a sensor in the locking mechanism assures the door is fullyshut), the system automatically locks the door without requiring anyfurther action by the user.

In addition, the system in one embodiment provides an automatic,retrievable record of each lock opening by date and time. When a lock iscapable of being opened by a number of people, the invention allows theowner or proprietor of the lock to keep a record of the users of thelock and of the time of each use. It is also possible to program eachlock so entry is allowed only during certain hours of the day or week.

This invention will be more fully understood in conjunction with thefollowing detailed description taken together with the drawings.

DESCRIPTION OF THE DRAWINGS

FIG. 1A shows how a universal key, in accordance with one embodiment ofthis invention, allows a user to more easily enter secured facilitiesand equipment during a typical day.

FIG. 1B shows a user carrying a universal key in accordance with oneembodiment of this invention approaching a door containing a lockreceptive to an ID code from the universal key.

FIG. 2 shows the relationship of a universal key, the ID code from theuniversal key, a lock unit, and a remote control system, in accordancewith this invention.

FIG. 3 shows the circuit diagram of a door reader capable of processingan ID code received from a universal key by a receiver and then sent tothe processor to drive a motor that activates a lock.

FIG. 4 is a schematic diagram of a universal key, incorporating aphysical on/off switch and motion sensors as part of the battery savingcircuit associated with one embodiment of this invention.

FIG. 5 is a schematic diagram of a door reader capable of processing anID code received from a universal key by a receiver and then sent to theprocessor to position a solenoid that opens and closes a lock.

FIG. 6 shows an exemplary universal key, in accordance with oneembodiment of this invention.

FIG. 7 is a schematic diagram of an alternative embodiment of a circuitfor processing a received signal to drive a relay that controls a lock.

FIG. 8 illustrates a sprocket structure associated with the universalkey's antenna to optimize omni-directional transmission distance, inaccordance with one embodiment of the present invention.

FIG. 9 illustrates a simple inexpensive receiver for use with a lockunit in one embodiment of the present invention, such as a lock for ashort range application.

FIG. 10 is a schematic diagram of a transceiver circuit associated withthe universal key, in accordance with one embodiment of the presentinvention.

FIG. 11 is a schematic diagram of a transceiver circuit associated withthe lock reader, in accordance with one embodiment of the presentinvention.

FIGS. 12A-12C are perspective views of a lock unit, in accordance withone embodiment of the present invention.

FIG. 13 is a perspective view of a lock unit, in accordance with anotherembodiment of the present invention.

DETAILED DESCRIPTION

This description is illustrative of the embodiments of the presentinvention only and not intended to be limiting. For example, in thisdetailed description, a universal key is described which includes aradio frequency (RF) signal transmitter for transmitting a unique IDcode that modulates an RF carrier signal. The present invention is notlimited, however, by the form of wireless signal transmission or anyparticular communication protocol between the transmitter and thereceiver of the ID code. To simplify discussion and to allow comparisonbetween figures, like elements are assigned like reference numerals.

FIG. 1A shows the path of a person using the universal key in accordancewith one embodiment of the present invention from the time the personleaves home until the person has completed a substantial part of theworkday. As shown in FIG. 1A, the user 110 leaves an apartment in anapartment building through door 102. In one embodiment, the lock on door102 does not allow the universal key to open the lock from inside theapartment, so the user opens the door manually, walks outside, and pullsthe door shut. Upon exit, the reader in the door lock picks up the IDcode transmitted by the universal key. The door lock remains open untilthe user travels beyond the read range of the locking system. At thatpoint, the door 102 automatically locks.

The universal key may be configured to communicate with an elevator 103to provide hands-free service to a user 110. For example, an elevatorcontrol system may detect the universal key as the user approaches theelevator shaft and will automatically summon the elevator to the floorwhere the user is located, without requiring the user to press a callbutton. The elevator control system may also access a storage devicethat stores one or more of the user's preferred floors (or floors he isallowed to access). Thus, when the user boards the elevator on theuser's residence level, the elevator may take the user to the garagefloor where the user's reserved parking slot is located (or to thegarage level where the user was last detected). Similarly, when theindividual returns to the apartment building later and boards theelevator on a garage level, the elevator may automatically proceed tothe individual's residence level (and also record the garage level wherethe user boarded the elevator). The automatic floor select may also beoverridden by the user.

Once on the garage level, user 110 may enter the garage through anotherdoor 104 unlocked by the universal key. Car 105 may also include a lockunit configured to receive the transmitted code from the universal key.If the ID coded signal from the universal key is recognized by thereader in the car 105 as the individual approaches the car 105, the cardoor is automatically unlocked. The automobile may further be configuredto allow a recognized user to start the car by pressing a button withoutrequiring the user to insert a mechanical key to effectuate ignition.User 110 then leaves the garage, opening gate 106 automatically with theID code from the universal key.

User 110 then drives to work and enters his work place through gate 107,again opened by the ID code transmitted from the hands-free universalkey. In similar fashion, the individual can use the universal key toaccess a number of secured locations, such as a campus gate and anothergarage. Leaving his car, user 110 then walks from the garage with thehands-free universal key on his person, thereby freeing the user's handsto carry other items.

As the user approaches lobby 111, the lobby door automatically unlocksin response to the ID code transmitted from the universal key. In oneembodiment, in which the locked door includes a powered openingmechanism, the presence of the universal key may both unlock the doorand cause the door to swing open for the user. Similar to elevator 103in the apartment building, an elevator 112 at the end of the lobby thenopens its door in response to the ID code from the universal key. Next,the door on the floor where user 110 departs the elevator 112automatically opens in response to the ID code from the universal key.The user then approaches the user's office and the door to the officeunlocks automatically in response to the ID code transmitted from theuniversal key.

The universal key can also be used to grant access to any locations,devices, or services which the user wishes to access during his or herwork day (e.g., locks on a closet 115 or storage area 119 associatedwith the user's office, or to a secured restroom 116). These locks mayinclude mechanical or electronic kinds (e.g., those protected by apassword or a personal identification number (PIN)). The universal keymay also be used to grant access to any piece of office equipment thatrequires an authorization, authentication or tracking code (e.g., faxmachine, copier 117, voicemail retrieval or long distance calls from atelephone system 118, and personal computer access).

FIG. 1B shows a user 110 approaching on foot the door 13 of her house.User 110 has in her purse a universal key 12 which is repeatedlytransmitting an ID code to the reader in lock unit 14. In otherembodiments, the reader may be provided with a transceiver whichtransmits an interrogation signal to the universal key 12. When theuniversal key 12 enters the range of the interrogation signal, theuniversal key 12 will transmit the ID code in response to theinterrogation signal. The universal key 12 transmits an ID code 15(either encrypted or unencrypted) to the reader in lock unit 14contained in and controlling the unlocking of door 13. The reader inlock unit 14 (an example of which is described below with reference toFIG. 2) is capable of picking up the ID code from universal key 12 onlywhen universal key 12 comes within the prescribed distance R from lockunit 14. Distance R associated with the front door is typically two (2)to three (3) feet, although other distances even as small as a fewinches can be selected, if desired. The short distance R between thereader in lock unit 14 and the universal key 12 within which the readerwould detect and respond to the signal from universal key 12 is designedto prevent door 13 from unlocking before user 110 comes close enough todoor 13. A prematurely unlocked door may allow unauthorized access tothe secured premise through the unlocked door 13.

As shown in FIG. 1B, the reader associated with lock unit 14 receivesthe ID code from universal key 12 on the person of user 110 outside door13. Typically, as will be described below, lock unit 14 is directionaland only unlocks the door in response to receiving an ID code signaltransmitted by universal key 12 from outside the house. As a result,when user 110 is inside the house, door 13 will not unlock even whenuser 110 is within the prescribed distance from door 13. Thisarrangement prevents door 13 from being unlocked inadvertently as user110 moves around the house. This directional recognition can beaccomplished in a variety of ways, as will be described in greaterdetail below. In one embodiment, the antenna of lock unit 14 is onlycapable of receiving signals generated on one side of door 13. Inanother embodiment, lock unit 14 is configured to identify the generallocation of the universal key (e.g., in front of the door or behind thedoor) and will only unlock the door in response to an ID code receivedfrom the desired direction or location (e.g., in front of the door).

FIG. 2 is a block diagram showing a universal key 12 and a lock unit 14,in accordance with one embodiment of the present invention. Universalkey 12 comprises an antenna 21, a transmitter 20, and a battery 19. Lockunit 14 comprises an antenna 23, a reader 29, a lockset actuator 25, anda lockset 26. Reader 29 comprises a receiver 22 and a processor 24. Lockunit 14 may be powered by a variety of mechanisms, e.g., a battery orrectified A/C power supply.

FIG. 2 shows that the universal key 12 includes antenna 21 andtransmitter 20 for transmitting an ID coded signal 15, which is receivedby antenna 23 in lock unit 14. As illustrated by the pattern 16, antenna23 and receiver 22 in lock unit 14 are capable of detecting the signal15 transmitted from universal key 12 only when universal key 12 iswithin the area contained within the line 16. Lock unit 14, thus, has adirectionally-sensitive and range-limited reader 29 that will preventlock unit 14 from responding to ID coded signal 15 when the universalkey 12 is located outside of the area bounded by line 16. A remotecontrol system 28 coupled to lock unit 14 via network connection 27 maybe provided to allow monitoring and remote programming of lock unit 14(e.g., to allow access by certain ID codes) or to query the accessrecords of lock unit 14.

FIG. 3 shows the circuit diagram of processor 24 of lock unit 14 capableof processing an ID code received from universal key 12. The wirelesssignal containing the ID code is received by antenna 23 and receiver 22,and is sent to the processor 24 to drive a motor that activates a lock.FIG. 3 shows a schematic diagram associated with microcontroller 304 inthe lock unit 14 for reading and processing ID coded signal 15 receivedfrom universal key 12 (FIG. 2), in accordance with one embodiment of thepresent invention. A connector 307 is provided for coupling processor 24to receiver 22, as will be described in greater detail below.

A power source represented by battery 305 (e.g., a 6-9 volts battery) inFIG. 3 powers the circuits (e.g., microcontroller 304) located in lockunit 14 in door 13 (FIG. 1B). Voltage regulator 308, a DC to DCconverter, comprises a three-terminal voltage regulator which provides asteady power supply voltage between 2.0 to 5.5 volts at terminal 303;this power supply voltage is also provided to other circuits throughpins 2 and 5 of connector 306. Alternatively, if the desired voltage is6 volts¹, a diode (e.g., a 1N914 or a 1N4001 diode) rather than avoltage regulator, may be used to produce a 0.7 voltage drop and aresulting 5.3 volts at terminal 302. A filter capacitor 313 is providedat terminal 303 to filter out noise. Additional filter capacitors 331and 332 (100 microfarad and 10 microfarad, respectively, in oneembodiment) are also provided on either side of voltage regular 308. ¹Use of a six (6) volt battery is typically not preferred because thelife of a six (6) volt battery is shorter than the life of a nine (9)volt battery using similar cells. However, six (6) volt batteries may berequired for certain door sizes and, thus, this embodiment of theinvention is capable of operating with either voltage level battery. Inanother embodiment, a different power source may be used.

A variable resistance (shown in FIG. 3 as including a potentiometer 342and two fixed resistors 341, 343) is used to select a desired voltagelevel. Receiver 22 (one example of which is shown in detail in FIG. 9)detects an RF signal from the universal key 12 (to be described later inconjunction with FIG. 4). The RF signal carries an ID code. Inaccordance with one embodiment, the RF signal may be an ASK(amplitude-shift-keying) encoded signal. In some embodiments, the IDcode may also be encrypted. Receiver 22 can also be implemented by anysuitable RF receiver configured to receive the desired signal frequency(e.g., RF receiver rfRXD0920, available from Microchip Technology Inc.,in Chandler, Ariz.). Receiver 22 transmits the ID code on pin 11(terminal 301) of connector 307, in a manner to be described below. Inthe case where the RF signal is ASK-coded, the power supply voltagelevel may be adjusted via potentiometer 342 to provide a threshold fordetecting the received ASK signal

Microcontroller 304 (e.g., flash microcontroller PIC10F200, availablefrom Microchip Technology, Inc.) receives the ID code on terminal 301and determines if the ID code matches one of the authorized storedcodes. Should a match be found, a signal is sent on terminal 309 frommicrocontroller 304 to turn on an actuator circuit. The actuator circuitincludes transistors 310, which drive actuator 25 (shown in FIG. 3 asmotor M1) to open the lockset 26 on lock unit 14. A filter circuitincluding inductors 318 and 319 and capacitor 320 is provided to filterout noise fed back from motor M1. Under certain conditions (e.g.,exceptional conditions), the actuator circuit can also be turned on andreset by closing switches 311 and 312, respectively. Microcontroller 304may be selected according to the features required by the lockingsystem.

In accordance with the illustrated embodiment, switches 311 and 312 areused to control the locking and unlocking of the lockset 26 using motorM1. In particular, switches 311 and 312 are used to control the durationof activation of motor M1 in response to receiving an authorized IDcode. Motor M1 rotates in only one direction and is connected to arotatable cam, which is connected to lockset 26, e.g., a deadboltlockset. When motor M1 rotates the cam through a certain angle, thelatch of the deadbolt is retracted from the strike plate and the door 13is capable of being opened. If motor M1 continues to rotate the cam, thecam to which lockset 26 is connected then causes the latch of deadboltto be pushed back into the strike plate until the latch is fullyinserted. At this time, the motor M1 again stops. The mechanical camsystem is thus like a locomotive drive in that the rotation of the camin one direction causes a back and forth linear motion of the latch inthe lock to which the cam is connected. In another embodiment, motor M1is controlled to turn and open the lock in one direction and to turn inthe opposite direction to subsequently close the lock.

Switch 311 monitors whether lockset 26 is locked or unlocked. Switches311 and 312 are normally open. Input terminals 316 and 317 tomicrocontroller 304 are typically pulled by pull-up resistors 321, 322to the voltage level of power rail 302. Capacitors 314 and 315 filterout the RF and motor noise associated with the system and motor M1. Whenlockset 26 is unlocked, terminal 316 receives a “0” signal, and whenlockset 26 is locked, terminal 316 receives a “1” signal. Switch 312 isa trigger switch that normally causes terminal 317 to receive a “1”signal, but will briefly pulse to a “0” signal when lockset 26 is eitherfully locked or fully unlocked.

When microprocessor 304 detects an ID code transmission on terminal 301,microprocessor 304 waits for a short period of time (e.g., 30milliseconds) for the transmission to complete, and then waits for theID code transmission to repeat. This delay helps to ensure thatmicroprocessor 304 receives the complete ID code transmission. Each IDcode may include a header portion to indicate the start of the ID code,in order to assist microprocessor 304 in synchronizing with the receivedsignal. After a complete ID code is received, microprocessor 304determines whether the received ID matches one of the ID codesauthorized to unlock lock unit 14. If the ID code matches, thenmicroprocessor 304 transmits a signal along terminal 309 to activatemotor M1, thereby unlocking lockset 26. When a “0” pulse is detected onterminal 317 (indicating that lockset 26 is either fully locked or fullyunlocked), microprocessor 304 checks the signal on terminal 316. If thesignal on terminal 316 is “0”, this indicates that lockset 26 is fullylocked, so microprocessor 304 continues activation of motor M1 until theterminal 317 detects another “0” pulse and the signal on terminal 316 is“1”. This indicates that lockset 26 is fully unlocked, so motor M1 isstopped.

After lockset 26 is fully unlocked, microprocessor 304 will initiate a“KeepOpen” routine to maintain lockset 26 in the unlocked position foras long as the authorized ID code continues to be detected on terminal301. When user 110 has traveled beyond the range of reader 29, such aswhen user 110 has gone through door 13 into the house, the ID code is nolonger received. Once a prescribed period of time (e.g., one second) haspassed during which the ID code is not detected on terminal 301,microprocessor 304 will initiate a “Lock” routine to relock lockset 26.A signal is transmitted on terminal 309 activating motor M1. Terminal317 is monitored for a “0” pulse, again indicating that lockset 26 iseither fully locked or fully unlocked. When the “0” pulse is received,the signal on terminal 316 indicates whether lockset 26 is locked orunlocked. Once the “0” pulse on terminal 317 is received simultaneouslywith receiving a “0” signal on terminal 316, motor M1 is stopped andmicroprocessor 304 begins awaiting the next ID coded signal.

To detect if door 13 is open, an additional switch (e.g., a mechanicaldetent) can be used with lock unit 14 to inform processor 24 whetherdoor 13 is open or shut. In one embodiment, a switch will be used inseries with the motor so that if door 13 is not closed, motor M1 willnot move. This switch is a safety precaution to ensure that door 13 mustbe completely shut before the deadbolt in lock unit 14 willautomatically enter the strike plate.

In other embodiments, switches SW1 and SW2 may operate in a variety ofways, depending on the type of lockset that is used in lock unit 14. Thesystem however is flexible so no matter which lockset is used in lockunit 14, microprocessor 304 can be programmed to let switches SW1 andSW2 inform the microprocessor 304 of the status of the door (i.e. whenthe door is open or closed).

As an optional embodiment, when battery B1 runs low, a warning light orother type of signal (for example, a brief beeping sound on a periodicor an aperiodic basis or a blinking light when a transmitted codedsignal is received) can be activated in the lock unit 14 to warn user110 to replace the battery so that the door can continue to be openedand closed using universal key 12. An LED can also be used as a warninglight but the LED will draw current and thus further decrease thebattery life. Alternatively, by making a transducer squeak for 50milliseconds (a duration that the ear can detect) when the battery islow upon receipt of ID coded RF signal 15, then the low battery willlast longer than if an LED is used as a warning light.

In one embodiment, motor M1 draws 300 milliamps and takes about a secondto unlock door 13 (i.e., to remove the latch of the deadbolt from thestrikeplate). Typically, door 13 will be controlled by a battery holdingapproximately 200 milliamps hours of energy. If it takes about a secondto unlatch the door and the motor draws 300 milliamps, then the door canbe unlatched about 2400 times before exhausting the battery. In analternative embodiment, door 13 may be capable of being wired so that anexternal power source can be used to operate the circuitry shown in FIG.3, including motor M1. In this case battery B1 would not be needed.

Should the circuit fail for any reason, either through a dead battery orfor any other reason, lock unit 14 can be mechanically overridden fromthe outside to unlock the door. A standard house key can be used toallow user 110 to enter the house. Thus, if the battery fails and thesituation is such that a user 110 must enter the house for safety or tosurvive, a manual key can be used to override the system.

In one embodiment, the microprocessor 304 may be programmed locallyusing six-pin header 306 shown in FIG. 3. If for some reason an ID codestored in microprocessor 304 must be changed, then this change isimplemented using the header 306. To delete an ID code, an appropriatedelete button integrated inside the lock unit 14 is pressed. To add akey, a button integrated inside lock unit 14 is pressed and the newuniversal key is quickly brought in proximity of the reader 29. Thereader 29 will sense the new ID code and submit the signal to terminal301 on microprocessor 304 from pin 6 on header 306, which allowsmicroprocessor 304 to be reprogrammed with a new code. This insures thatif a key is lost or if someone is able to intercept the code being usedto unlock door 13, the code can be easily changed, more quickly and withless hassle than a lock currently can be rekeyed. Thus, the lock unit 14of this invention is capable of being used on rental units and in hotelunits, which require quick and easy change of the ID code required toopen the lock. Typically, the memory is such that the memory can bereprogrammed a large number of times. Commercially available flashmemory or electrically erasable programmable read only memory can beused to store the code. In other embodiments, the microprocessor 304 maybe programmed remotely, as will be described in greater detail belowwith respect to FIG. 7.

Lock unit 14 contains an antenna 23 for receiving signal 15 fromuniversal key 12. In some embodiments, antenna 23 comprises adirectional antenna unit that will enable lock unit 14 to receivesignals only from one direction and only within a certain distancerange. Antenna 23 can be provided as a separate component or can beintegrated onto the printed circuit board containing the circuitry forreceiver 22 and processor 24.

Solenoid-Driven Lock Unit

FIG. 5 shows a schematic diagram of an alternative embodiment of aprocessor for controlling a solenoid-driven actuator for a lock unit. InFIG. 5, the power supply 505 also provides six (6) volts or nine (9)volts. Capacitors 531 and 532 (100 microfarad and 10 microfarad,respectively) act as filters as they do in the circuit of FIG. 3 and thevoltage regulator 508 is, e.g., an LT1121-5 three (3) terminal regulatorfrom Linear Technology. The voltage output from voltage regulator 508 issent to the microprocessor 504, which is, e.g., a PIC12F675microprocessor, also from Microchip Technology, Inc. Capacitor 513 (0.1microfarad) again filters the supply voltage that is input to pin 1V_(CC) of microprocessor 504. Ground (V_(SS)) is provided on terminal530. Switches 511 and 512 are shown connected through resistors 531 and532 (each 4.7 k ohms) to terminals 516 and 517, respectively, ofmicroprocessor 504. The voltage from voltage regulator 508 is providedon terminal 503 to a connector 507. Connector 507 is coupled to receiver22 to receive an electronic signal generated by the receiver 22receiving the ID coded RF signal from the universal key. As with FIG. 3,a variable resistance including a potentiometer 542 and two fixedresistors 541, 543 is used to select a desired voltage level for theoutput signal on terminal 501 to microprocessor 504. The values of theresistors 541-543 in one embodiment are shown in FIG. 5.

If the ID code on the signal being transferred on terminal 501 matchesan ID code stored in microprocessor 504, microprocessor 504 then sends asignal to driver circuit 550 on terminals 551 and 552. Driver circuit550 may comprise, e.g., part no. SN754410 integrated circuit from TexasInstruments Inc., of Dallas, Tex. Driver circuit 550 then drivessolenoid S to unlock the lockset. Solenoid S is reversible and followingthe opening and re-closing of the door, microprocessor 504 will thencause the solenoid S to drive the deadbolt back into the strike plate.Switches 511 and 512 can be used to control the operation of solenoid S,similar to the operation of switches 311 and 312 described above withrespect to FIG. 3.

Universal Key

FIG. 4 shows a schematic diagram of an exemplary universal key 12, inaccordance with an embodiment of the invention. The universal key 12broadcasts the coded signal on, e.g., a carrier frequency of either433.92 MHz or 915 MHz in the United States, or 868 MHz in Europe. Othertransmission frequencies may also be used, such as in other countrieswhich may require the use of other frequencies.

The universal key 12 in FIG. 4 includes microcontroller 400, which canbe, e.g., model no. rfPIC12F675H, provided by Microchip Technology,Inc., in Chandler, Ariz. Microcontroller 400 contains both a computer(e.g., a microprocessor) and a built-in transmitter. Connector 430provides access to terminals 404, 418 and 419 to allow programming ofthe microprocessor portion of this microcontroller 400. Terminals401-404 and 417-420 allow selected signals to be sent to and receivedfrom the microprocessor portion of the microcontroller 400.

The power supply used can be, e.g., a half sized AA battery, half sizedD battery, or any other appropriate power cell that provides the desiredvoltage, which is from 2.8 volts to 5.5 volts in the illustratedembodiment. In one embodiment, the battery (not shown) provides 3.6volts V_(DD) to terminal 401 of microcontroller 400. The notation“V_(CC)=2.8 Volts to 5.5 Volts” indicates the range of acceptablevoltage levels provided to the circuitry in FIG. 4 from the powersupply.

In some embodiments, the universal key is always on. However, theembodiment illustrated in FIG. 4 includes an on/off switch 440 that maybe used by the user to deactivate the universal key should the needarise (e.g., while flying on a commercial airline). Switch 440 will, inone embodiment, comprise a reed switch and a magnet. When the magnet isplaced near the reed switch, the switch remains open so no voltage willget to the device. When the magnet is moved from the reed switch, thereed switch will resume its normal position allowing voltage to betransmitted to microcontroller 400 and thereby turning on the universalkey to send out periodic signals to the environment. In a secondembodiment, switch 440 will be comprised of the battery compartment,battery and lid. After the battery is inserted in the batterycompartment, the lid is inserted and turned a half turn. This willcreate a watertight seal but will not create a closed circuit. When thelid is turned an additional half turn, the battery is pushed forward,thus making contact with the electrical leads and completing thecircuit. Only in this position will the microcontroller 400 be poweredand the universal key transmit.

One embodiment also includes switches 441 and 442, which comprise motionsensors that determine when the universal key is moving. If eitherswitch 441 or 442 does not sense activity for a specified time, theelectronic circuitry in the universal key goes into a sleep mode (inwhich no signals are transmitted), which prolongs battery life. Once themotion detectors determine the universal key is in motion, the circuitryawakens and allows the universal key to send two (2) pulses a second tothe environment. This will activate any lock within range of theuniversal key. In one embodiment, switches 441 and 442 comprise motionsensors (P/N NM3001-1) manufactured by Signal Systems International, ofLavallette, N.J. When moved, they cause connections to be periodicallymade between the battery and terminal 404 of microcontroller 400,thereby turning on microcontroller 400 for a specified period of time.Frequent motion will result in the universal key remaining oncontinuously. In other embodiments, the motion sensors may beimplemented using other mechanisms, as would be understood by those ofordinary skill in the art.

Crystal 444 provides a frequency of 28.593750 MHz to terminal 405 ofmicrocontroller 400. The structure inside microcontroller 400 includes aphase locked loop that multiplies this frequency by 32 to get to exactly915 MHz. The operation of microcontroller 400 is described in productliterature from Microchip Technology Inc., such as the Data Sheet forrfPIC12F675K/675F/675H, 20-Pin FLASH-Based 8-Bit CMOS Microcontrollerwith UHF ASK/FSK Transmitter, which is hereby incorporated by referencein its entirety. Terminal 402 connects the microprocessor portion ofmicrocontroller 400 to the transmitter portion of microcontroller 400.The transmitter portion of microcontroller 400 contains analog circuitscapable of transmitting an RF signal from terminal 411 to the antenna450, thereby causing a 915 MHz signal to be transmitted from antenna450.

In the illustrated embodiment, the code sent out from the universal keyincludes six 8-bit codes. The universal key sends out a 25 millisecondburst every half second. Between each 25 millisecond burst, theuniversal key sleeps. This continues so long as the motion sensorsindicate that the user is moving and thus the universal key should besending out a signal. Thus, the universal key operates on about a 5%duty cycle when the key is activated. The ID coded signal specificallysent by the transmitter portion of the microcontroller 400 can containany one of up to approximately 81 billion codes. Thus, the code numberassociated with each person can be truly unique to that person.

Microcontroller 400 has two grounds. One ground is associated with themicroprocessor portion of microcontroller 400 on terminal 420, and theother ground is associated with the transmitter portion ofmicrocontroller 400 on terminal 410. Terminal 408 associated with thetransmitter is connected through a 47 k ohm resistor 451 to ground. Thisresistor 451 sets the RF output power.

Universal Key Antenna

As shown in FIG. 4, antenna 450 is coupled to terminal 411 of thetransmitter portion of microcontroller 400. An inductor 452 in parallelwith the 220 ohm resistor 454 connects the antenna 450 to a powersupply, which can be the same as or distinct from the power supplypowering microcontroller 400. Resistor 454 broadens the frequencyresonance of the inductor 452.

Various types of antennas 450 may be used for the universal key. FIG. 8shows a printed circuit board layout for a quasi-omnidirectional antenna450 in accordance with one embodiment of the present invention. Whentransmitting an RF signal, output power is optimized when the antennahas a length that is a multiple of one-quarter of the wavelength of thetransmitted RF signal. In the present embodiment, the RF signalfrequency is 915 MHz, thereby making the preferred antenna lengthapproximately 3″ or some multiple thereof. However, it is also desirableto provide a universal key with compact dimensions so that the key maybe unobtrusively carried by the user. FIG. 6 shows an exemplaryuniversal key 12 that is 2″ long, 1.25″ wide, and 0.375″ thick, which issmaller than the minimum preferred antenna length of 3″.

As shown in FIG. 8, it is possible to fit a 3″ long antenna into asmaller package by arranging the antenna in a serpentine or meanderingshape Unfortunately, the electromagnetic signals generated by thecurrent passing through the radial portions of the antenna (e.g.,portions 801 and 802) will cancel each other out due to oppositeelectromagnetic fields generated by the oppositely directed currents,thereby diminishing the overall transmission power of the antenna.However, the resulting output power will still far exceed what would begenerated by an antenna with a length other than a quarter wavelengthmultiple. Accordingly, the antenna can be an effective radiator with theamount of power being controlled by the meandering sprocket pattern ofthe antenna. This design minimizes the planar area within which aquarter-wavelength long antenna can be housed, while also minimizing theundesirable signal cancellation effects of oppositely directed currents.

The illustrated universal key antenna is capable of broadcasting asignal well over 300 feet. To control the distance at which a signalfrom the universal key will open a lock unit, the antenna, readercircuitry, and other electronics within the lock unit are designed to beable to “hear” the universal key at a specific distance and from aprescribed direction. In other words, the reader will only recognize asignal from a prescribed direction and having a minimum prescribedstrength. The distance within which the universal key must be from thelock unit for the lock unit to detect the signal from the universal keyis determined by the strength of the signal that reaches the processorcircuitry, which is controlled by the gain of the antenna and thereceiver circuitry.

Garage Lock Reader

FIG. 7 shows a schematic diagram associated with the circuitry forreading and processing the signal received from the universal key, andfor reading computerized control signals from a remote control system 28at a remote location (as shown in FIG. 2). This circuitry can be used,e.g., to control commercially available automatic garage door openers,as will be described in greater detail below.

This circuitry performs a similar function to the circuitry described inFIG. 3. Some differences are that the circuit in FIG. 7 uses a 9VDCpower supply, receives control signals from a remote source (e.g., RS232control signals received from an RS232 serial source, such as acomputer), in addition to the ID code signals from the universal key.This embodiment also contains additional circuits, said circuitsincluding additional flash memory 764, time and date keeper with batteryback-up 762, and a mechanical relay circuit capable of triggering theopening and closing of non-proprietary third-party locks and gates.These differences are further described in detail below.

A connector 727 is coupled to a receiver 22 (one embodiment of which isshown in detail in FIG. 9), which detects the RF signal from universalkey 12. A second input/output connector 766 is coupled to remote controlsystem 28. Connector 766 receives an RS232 signal input from acomputerized source, such as an RS232 signal from a computer, or from a“bridged” converter whose source is any of several existing signals andprotocols, which include but are not limited to Ethernet, UniversalSerial Bus (USB), modem, RS485, RS422, or similar communicationprotocols. The RS232 input signals arrive on terminal 722, pass througha limiting 22K ohm resistor 765 and enter microcontroller 760 throughterminal 713, where they are decoded by the software and acted upon.

In one embodiment, the RS232 input signals are single character commandsto microcontroller 760. These commands request certain actions frommicrocontroller 760, such as reading/setting the time and date containedin the time and date circuit 762 (e.g., integrated circuit, part no.DS1302, by Dallas Semiconductor, of Dallas Tex., or other similar timeand date chips). Additional commands include, e.g., requesting a list ofuniversal key codes, showing if they are enabled or disabled, andcommands that cause particular universal key codes to be enabled ordisabled. Further commands may include requesting a memory dump ofrecent activity, which consists of time stamped system hits fromuniversal keys, including the date, time and universal key ID code.

Microcontroller 760 (e.g., a PIC16F676 microcontroller from MicrochipTechnology, Inc., in Chandler, Ariz. or other similar microcontroller),contains software that processes the received commands and respondsaccordingly by sending an RS232 response signal out of terminal 711 toconnector 766, and thence out to the requesting authority.

In other embodiments, the readers described above with respect to FIGS.3 and 5 may be provided with a similar mechanism for enabling themicroprocessors to be remotely programmed.

Voltage regulator 728 processes the 9VDC input power applied toconnector 729 and outputs a regulated +5VDC on terminal 730 for use bythe other components using terminal 730 as a power rail. These othercomponents include the RF receiver 22 coupled to connector 727,time/date IC 762, microcontroller 760, flash memory 764, andrelay-driver transistor 731 powered through a series connection with therelay coil 732.

The above power distribution uses capacitors 742, 744, 745, and 746 asnoise filters on terminal 730. Capacitor 741 is used as a noise filteron the 9VDC input power line and capacitor 743 is used as a noise filteron the 3.3VDC supply rail from the back-up battery source 750.

Similar to FIG. 3, variable resistor 752 is used to provide the desiredinput voltage to microcontroller 760 from connector 727. An audiotransducer 767 may also be connected to terminal 702 of microcontroller760 to provide an audio test output while the serial signal is inprogress. A relative signal strength indication (RSSI) is generated byRF receiver 22 (FIG. 2) and is received at terminal 703 ofmicrocontroller 760. The software in microcontroller 760 can use theRSSI signal in situations where it is required to ascertain if auniversal key is approaching (RSSI increasing) or departing (RSSIdecreasing) from the RF receiver antenna.

The flash memory chip 764 (e.g., a 256 byte 24LC256 serial flash memorychip from Microchip Technology or other size memories from MicrochipTechnology or other manufacturers) is controlled by software inmicrocontroller 760. Microcontroller 760 communicates serially with theflash memory 764 through terminals 708, 709, and 710. Microcontroller760 communicates serially with time/date IC 762 through terminals 705,706, and 707. Time/date IC 762 normally is powered by the +5VDC supplyrail on terminal 730, but derives back-up power through 3.3V battery750, which allows the time/date IC 762 to continue functioning for longperiods should the main 9VDC power be interrupted. Time/date IC 762 usescrystal 751, e.g., a 32.768 KHz crystal, for its time-base. Upon receiptof an ID code from a universal key, microcontroller 760 fetches the timeand date from time/date IC 762, and then stores the received ID codewith the time and date of reception into flash memory 764. The softwarein microprocessor 760 can request a “memory dump” of the contents offlash memory 764, when so commanded by a signal from the RS232 serialinput from connector 766.

The microcontroller software determines whether the ID code receivedfrom a particular universal key is either valid of invalid. If invalid,the event is saved in flash memory 764 and no further action is taken.If valid, the event is saved in flash memory 764 and microcontroller 760causes a mechanical relay contact closure, or opening as required, tooperate non-proprietary third-party lock and gate equipment. This actionis effected when microcontroller 760 places a “1” on terminal 712 goingthrough 1K ohm resistor 768 to the base of bipolar transistor 731. Thissaturates and draws current through the mechanical relay coil 732,causing relay 732 to open the contact connection between terminals 772and 773, and to close the contact connection between terminals 772 and771. A diode 774 across relay coil 732 is a protection device thatlimits the voltage across relay coil 732 to a low value when coil 732 isde-energized. The diode LED 775 across relay coil 732, in series with220 ohm resistor 776, is an indicator that illuminates while the relayis energized. The mechanical relay contacts are of type single-poledouble-throw (SPDT) and connect to terminal block 780. Many third-partygates and locks employ contacts of the type provided as auxiliaryswitches to energize their motor controllers that open and close theirgates and locks.

Lock Receiver

Various types of receivers may be used in lock units for receivingwireless signals from universal keys. As described above, one exemplaryreceiver is RF receiver rfRXD0920, available from Microchip TechnologyInc. In accordance with another embodiment, the low cost, lowsensitivity, and low power RF receiver shown in FIG. 9 may be used todetect and amplify the signal from the universal key and extract theuniversal key ID code.

The RF signal impinges on the antenna 900 coupled to terminal 901 andcreates a very weak electrical signal which is an analog of the RFsignal. The antenna 900 is of such design as to offer some selectivityto the frequency of the RF signal from the universal key and further, tooffer some insensitivity to the other signals in the RF spectrum.

The electrical signal on antenna 900 is presented to a bandpass filter,shown as filter 905 in FIG. 9. Bandpass filter 905 is a surface acousticwaveform (SAW) filter, but may in other embodiments be any other type offilter that further increases the selectivity of the RF electricalsignal analog from antenna 900. This signal is passed to the anode of asmall signal Schottky diode 906 where the signal is rectified. Theillustrated embodiment uses a 1N5711 Schottky diode manufactured bySTMicroelectronics of Geneva, Switzerland, but diodes performing asimilar function may also be used. This rectification, also called RFdetection by those skilled in the art, recovers the original modulationsignal impressed upon the RF signal by the universal key, and therebyretrieves the transmitted code ID from the universal key.

A power rail 902 is provided having, e.g., +5V, although other powerrail voltages may also be used. Capacitors 931 and 932 filter electricalnoise that may be present on power rail 902. The Schottky diode 906 isforward biased by current from series resistors 911 and 912 attached topower rail 902, to further enhance its signal detection ability. Thisbias current causes a small voltage to appear across diode 906. Asimilar situation exists in the circuit formed by series connectedresistor 913, resistor 914, and diode 907. The voltage drops acrossdiodes 906 and 907 remain almost identical as the ambient temperaturevaries, and these diodes are said to “track” the temperature changes.This “tracking” function is designed to present a common mode voltage tothe comparator 920, which can be, e.g., a model no. LTC1440 comparatorby Linear Technology Corp. of Milpitas, Calif. Although the LTC1440comparator is used in this embodiment, other comparators can be used.Terminal 925 on comparator 920 shows a connection to an internal zenerdiode 930 that is part of the LTC1440 device, but its function is notused in this embodiment.

With no signal from the antenna, the output of comparator 920 is biasedto zero volts due to the fact that the voltage on terminal 924 is veryslightly higher than the voltage on terminal 923. This bias is due to ahigher voltage on the top of resistor 912 than appears at the bottom ofresistor 914.

When an RF signal from antenna 900 is detected by diode 906, the signalpasses serially to an “envelope extractor” circuit comprised of resistor912 and capacitor 931. This extracted envelope is a low amplitudeversion of the coded ID transmitted by the universal key. The lowamplitude signal is sufficient to cause the output signal fromcomparator 920 to reproduce this low amplitude signal at a highamplitude suitable for use by a microcontroller, such as microcontroller304 in FIG. 3.

Universal Key Transceiver

In the above description, one-way transmission from a universal keytransmitter to a lock unit reader is described. Alternatively, theuniversal key and the lock unit may include transceivers to providebidirectional communication. A transceiver in the lock unit may beconfigured to send out an interrogation signal sufficiently strong to bereceived by a transceiver in the universal key and “wake up” theuniversal key when the key comes within a selected distance of the lockunit. The universal key in this embodiment would always be asleep untilthe key receives the RF signal from the transceiver in the lock unit. Assoon as the universal key receives that signal, the key would inresponse send out an RF signal having an ID code unique to theindividual holding the universal key. When the lock unit's transceiverreceives this transmitted signal and the processor determines that theID code is acceptable, the lock unit actuator would cause the lockset tobe activated to allow the door to be opened. One advantage of providingtwo-way communication between the universal key and the lock unit isthat encryption may be used for the transmissions. In addition,universal key battery life is improved since the universal key does nottransmit any signal until prompted by the lock unit transmission. Theuniversal key then returns to a sleep mode.

FIG. 10 shows a schematic diagram and certain circuit componentsassociated with universal key transceiver 1000. Universal keytransceiver 1000 comprises a transmitter portion 1010 and a receiverportion 1011 coupled to an antenna 1003. Transmitter portion 1010 issimilar in design and operation to the transmitter shown in FIG. 4, andthe receiver portion 1011 is similar in design and operation to thereceiver shown in FIG. 9. These two portions 1010, 1011 enable thecombined transceiver 1000 to both transmit and receive RF signals fromanother transceiver. In this embodiment, the other transceiver residesin the lock unit, but can also reside in any other device that providesaccess control using the universal key.

One advantage of using two transceivers with bidirectional communicationis the ability to negotiate with other transceivers for the purpose ofoperating a third circuit. In this embodiment, the third circuit opensand closes a lock when certain identification is established throughtwo-way encryption negotiation, but can also operate other mechanismsand systems.

The output terminal 1001 of receiver portion 1011 carries a demodulatedRF signal that contains appropriately coded information that is input tomicrocontroller 1400. In this embodiment, the microcontroller softwarebases its own subsequent RF signal response upon the encryptionnegotiation requirements of the transmitter portion 1010 and thereceiver portion 1011, although other communications may also takeplace.

In this embodiment, transmitter portion 1010 and receiver portion 1011share a single antenna 1003 for use by transmitter portion 1010 totransmit an RF signal and for use by receiver portion 1011 to receive anRF signal. Therefore, the RF output terminal of transmitter portion 1010is coupled to an antenna that is also coupled to the RF input terminalof receiver portion 1011 by a capacitor 1004. However, other methods ofcoupling the RF energy between the two portions 1010, 1011 and thesingle antenna 1003 may also be used.

Lock Reader Transceiver

FIG. 11 shows a schematic diagram and certain circuit componentsassociated with the lock reader transceiver 1100, in accordance with oneembodiment of the present invention. Lock reader transceiver 1100comprises a transmitter portion 1110 and a receiver portion 1111 coupledto an antenna 1102. Transmitter portion 1110 is similar in design andoperation to the transmitter shown in FIG. 4, and the receiver portion1111 is similar in design and operation to the receiver shown in FIG. 3.These two portions 1110, 1111 enable the combined lock readertransceiver 1100 to both transmit and receive RF signals from anothertransceiver (e.g., universal key transceiver 1000).

In this embodiment, the microcontroller 1104 may comprise, e.g., a modelno. PIC16F676 microcontroller, manufactured by Microchip Technology. ThePIC16F676 microcontroller has a larger number of I/O pins than thePIC10F200 microcontroller 304 described above with respect to FIG. 3. Inother embodiments, any microcontroller with an adequate number of I/Opins may be used.

In this embodiment, the extra microcontroller I/O pins are provided toenable additional functionality. One additional function is to detect a“door closed” switch, which, in the microprocessor software of themicrocontroller 1104, inhibits inserting the deadbolt into the strikeplate until the door is completely closed. Other additional I/Ofunctions may include providing user switches or pushbuttons to commandthe microcontroller software to delete a previously valid ID code,and/or to add a new valid ID code to the memory of microcontroller 1104.Another I/O function may be providing an audio alarm that indicates a“low battery voltage” condition. In other embodiments, the additionalmicrocontroller I/O pins may also be used for other purposes.

In this embodiment, antenna 1102 comprises a directional antenna thatreceives RF signals emanating from outside of the door with highsensitivity and RF signals emanating from the inside of the door (e.g.,inside the apartment or room) with very low, or zero, sensitivity. Inother embodiments, non-directional antennas can also be used for otherlocking systems.

The lock reader transceiver 1100 shown in FIG. 11 provides a two-way RFcommunication system. An input signal on terminal 1124 ofmicrocontroller 1104 is the eventual result of an RF signal from an RFreceiver plugged into header 1107. The output signal on terminal 1123 ofmicrocontroller 1104 goes to microcontroller 1150. In this embodiment,the microcontroller software bases its own subsequent RF signal responseupon the encrypted negotiation requirements of both the microcontrollers1104 and 1150, although other communications may also take place.

In this embodiment, the microcontrollers 1104 and 1150 share a singleantenna 1102 for use by microcontroller 1150 to transmit an RF signaland for use by microcontroller 1104 to receive an RF signal by way ofheader 1107. Therefore, the RF output of microcontroller 1150 is coupledto an antenna 1102 that is, in turn, coupled to the RF input of themicrocontroller 1104 by capacitor 1103. However, other methods ofcoupling this RF energy between the two microcontrollers 1150 and 1104and the single antenna 1102 may also be used.

Directional Sensitivity

As described above, in some embodiments, the lock unit is configured toreceive only signals transmitted on one side of the secured portal(e.g., the front door to a home). This can be accomplished in a varietyof ways, but in one embodiment, to make the lock unit sensitive to atransmitted signal coming from outside the door, but not from inside thehouse, a physical barrier to electrical signals is used. For example, ametal plate may be placed between the antenna 23 and the inside of thehouse. The metal plate blocks all transmission signals originating frominside of the house to the antenna 23 and thus prevents signals whichmay come from inside the house from activating the lock.

Other mechanisms may be used for selectively receiving universal keysignals from a particular direction. Depending on specific user need,with some locks omni-directional antennas can be used while with otherlocks, very specific directional antennas can be used. In oneembodiment, the lock unit includes two antennas, one receiving signalspreferentially from a first side of the door and a second receivingsignals preferentially from an opposite side of the door. If a signal isdetected by the antennas, the reader 29 will compare the two signals andwill conclude that the universal key is located on the side of the doorhaving the stronger signal. If a signal is thus detected coming from oneside of the door, the door will not be unlocked whereas if a signal isdetected as coming from the other side of the door, the door will beunlocked.

Lock Unit

FIGS. 12A-12C show various views of a lock unit 1200 that could bemounted to a door, in accordance with one embodiment of this invention.FIG. 12A is a perspective front view of the lock unit 1200, showing theside of the lock unit 1200 that would face inside of the room. FIG. 12Bis a cross-sectional side view of lock unit 1200. FIG. 12C is a backview of lock unit 1200, showing the side of lock unit 1200 that wouldface the door onto which lock unit 1200 is mounted.

In this embodiment, lock unit 1200 comprises a housing 1202 and abattery bay 1204 containing four AA batteries 1206. In otherembodiments, other types of power sources may be used, such as othersize batteries or rectified A/C power. A battery bay cover would also beprovided but is not shown in the figures for clarity. Five (5) switches1205 are exposed in FIG. 12A. These switches 1205 are coupled tomicrocontroller 1104, as shown in FIG. 11, to enable local programmingof microcontroller 1104. These switches may also be used to allow forthe addition of new features and functionality for future designs. Alock region 1210 in the housing 1202 contains the lockset actuator andthe gearing necessary to open and close the lockset. This embodimentutilizes a motor 1212 (shown in FIG. 11; not shown in FIGS. 12A-12C) todrive the lockset.

The cross-sectional view in FIG. 12B exposes the door reader 1220 oflock unit 1200. In this embodiment, door reader 1220 comprises threeseparate PCBs, base PCB 1221, chipset PCB 1222, and antenna PCB 1223.Base PCB 1221 attaches to housing 1202 and includes switches 1205 andthe electrical interface to batteries 1206. Chipset PCB 1222 couples tobase PCB 1221 and contains the majority of the circuitry utilized toimplement the receiver and processor. Chipset PCB 1222 receives powerfrom base PCB 1221.

Antenna PCB 1223 comprises a dielectric layer having a planar layer ofcopper applied to the side of antenna PCB 1223 opposite base PCB 1221.The planar layer of copper serves as the director for the lock unitantenna. Another conductive layer is provided on the opposite side ofthe dielectric layer to serve as a grounded reflector for the antenna.The side of base PCB 1221 facing antenna PCB 1223 includes a planarcopper layer which serves as the driven element for the antenna. BasePCB 1221 is attached to antenna PCB 1223 using standoffs, which separatethe driven element from the director by a small gap, e.g. ⅛″. The sideof base PCB 1221 facing battery bay 1204 includes a layer of groundedcopper which serves as a reflector for the antenna and blocks RF signalsoriginating from inside the room from reaching the lock unit antenna.This ensures that only RF signals generated by a universal key locatedoutside of the room are received by lock unit 1200. The driven elementand the reflector are coupled in order to reduce the standing waveratio. This arrangement provides an antenna that is directionallysensitive with a sufficiently high gain, while maintaining a very smallform factor.

FIG. 13 is a perspective view of a lock unit 1300 mounted onto a door1301, in accordance with another embodiment of this invention. In FIG.13, various portions of lock unit 1300 are not shown or are shown inwireframe for clarity. In contrast with motor-driven lock unit 1200 inFIGS. 12A-12C, lock unit 1300 includes a solenoid 1308 which is poweredby a battery 1306. Lock unit reader 1320 controls solenoid 1308 asdescribed above with respect to FIG. 5. When activated by reader 1320,solenoid 1308 drives vertical movement of pin 1310. Pin 1310 is coupledto universal joint 1311, which in turn is coupled to connecting rod1312, and then to thumb latch 1314. Accordingly, movement of solenoid1308 causes thumb latch 1314 to move up and down. Thumb latch 1314 iscoupled to gearing such that when thumb latch 1314 is raised by eithersolenoid 1308 or manually by a user, the spindle of the lockset rotates,thereby withdrawing the latch out of the door jamb.

ALTERNATIVE EMBODIMENTS

In other embodiments, a variety of methods may be used to initiatecommunication between the universal key and the lock unit. For example,another embodiment uses a physical proximity detector to detect whensomeone enters a prescribed area around the front of the door, similarto the proximity detectors used in many commercial buildings to opendoors as customers approach. As a person approaches the door, theproximity detector will instruct the transceiver in the lock unit totransmit an interrogation signal. If a compatible universal key iswithin range, the universal key will respond to the interrogation signalfrom the lock unit by transmitting its ID code. This ID code will thenbe received and processed by the lock unit, as described above.

In accordance with embodiments of the present invention, a compact andlightweight portable unit that can be easily and un-noticeably carriedin a shirt pocket, pants pocket or purse provides a hands-free,wireless, lock opening function. In some embodiments, the wireless lockopener is constantly on for the user and unlocks doors or otherlock-controlled structures when within a predetermined distance, whichmay vary from one type of locked structure to the next. The same keyunit may be used for all types of locks including, for example, those ona house door, garage door, parking entrance gate, office building lobby,office elevator, main office door and more secure dwelling spaces in anoffice, such as secured computer server closets and maintenance closets.The key unit will also work to access electronic locks, such as thoseassociated with devices requiring passwords or personal identificationnumbers (PINs). Unlike conventional garage door openers, the constantlyon wireless key does not have an unlock activation button for initiatingan unlocking operation at a locked structure. Instead, as thekey-carrying user approaches the locked structure, at a predetermineddistance from the locked structure, where the distance varies dependingon the configuration of the lock on the structure, the lockautomatically unlocks.

If the locked structure is the front door of a residential living area,the locking system may be configured to unlock the front door only whenthe universal key is within a very short range, e.g., 2 to 3 feet.Because the user will be approaching the front door on foot, theapproach speed is quite low. Therefore, unlocking the door such a shortdistance away will not result in undesirable delays for the user. Incontrast, if the locked structure is a door to a secured garage, thenthe user will likely be in an automobile and traveling at a much highervelocity, so it may be desirable for the locking system to be configuredto unlock the garage door at a much larger distance. For example, thedistance at which unlocking of garage doors occurs can be 50 feet ormore. More specifically for garages, the distance at which unlocking isinitiated may be set to coincide with the distance at which anapproaching car is essentially committed to driving into the garage.This can vary from one location to another. In some instances, thelocked structure unlocks at the precisely controlled distance only ifthe key-carrying user approaches from a particular direction but notfrom another direction. This is useful for applications such as separateentrance and exit driveways for commercial parking lots among otherplaces.

In one embodiment, the universal key is contained within awater-resistant molded plastic casing that is able to absorb mechanicalshock when accidentally dropped, for example, into a wet area where theinside circuitry may otherwise become short circuited. It is alsodesirable for the key to be able to remain operational over a wide rangeof temperatures without variance of its radio frequency power outputlevel. Each locked structure has an antenna whose reception range istuned so that the lock reader will be able to detect pulsed outputsignals from the universal key only within the desired distance. Theuniversal key transmitter has an antenna that is omni-directional so thesame signal strength is provided irrespective of the orientation of thekey unit within a user's pocket or elsewhere. On the other hand, somereceivers associated with a lock unit may have directional sensitivityfor allowing opening from a first distance in one direction and from asubstantially different distance or none at all in another direction.

In some embodiments, it may be desirable for the universal key to betemporarily shut off. This may be desirable in cases where the key unitis being taken on an aircraft and government regulations require radiotransmitters to be shut off, or in other cases where the user does notwant his device to be active, such as because a prowler is nearby orbecause the user is going away on vacation and wishes to preservebattery life. A switch may be provided on the key to turn thetransmission on or off. In some embodiments, the key may be providedwith a difficult-to-access slide switch in order to avoid the key frombeing turned off inadvertently while in the user's pocket, for example.

In some embodiments, it may be desirable to utilize a power sourcespecifically designed for use in RF applications. For example,PulsesPlus™ batteries by Tadiran of Port Washington, N.Y., arerechargeable lithium-ion type batteries that may be suitable for variousembodiments. These batteries are especially designed to provide longbattery life in high current pulsed RFID applications. In otherembodiments, ordinary alkaline batteries or button cells may be used aswell.

Several techniques may be used to further prolong battery life. First,pulsed RF identification code sequences (approximately 48 bits long orlonger) may be sent out only once every half second or over a longerspace of periodic dead time. The duty cycle for on versus off isapproximately 5%, but may vary in other embodiments.

A second method of prolonging battery life provides for detecting whenthe universal key is essentially motionless and at such times, thepulsed RF outputs are suppressed. A watchdog computer program monitors amotion detector, and if there is no movement detected beyond a specifiedwatchdog cycle, the unit is put into low power sleep mode. Any movementtriggers the watchdog program to terminate the sleep mode and resumenormal transmission. The amount of motion sufficient to keep the unitactive and sending out pinging RF signals may vary in differentembodiments. For example, it may be desirable for small vibrations, suchas those experienced by a user seated inside a car which is running inidle, to provide sufficient movement so as to maintain the universal keyin active transmission mode.

In various embodiments described above, the lock reader comprises auni-directional transmission scheme in which the universal key servesonly as a transmitter and the lock unit serves only as a receiver. In analternative embodiment, two-way communication is allowed where thealways-on and always-carried universal key listens for initial pingingtransmissions from nearby lock units. In essence, the lock output pingsrepresent the question: “is any one out there who will respond to myinquires?” The key unit detects these inquires when the key is closeenough and then answers back with a signaling sequence that says “yes Iam here and here is my unique personal identification code.” If theunique personal identification code matches one for which access isallowed at the access gateway, the unlock operation is initiated. Withthis two-way communication methodology, a third means of prolongingbattery life is possible. With this embodiment, the universal key isalways in sleep mode until the key travels within range of aninterrogation signal from a lock unit transmitter. At that time, theuniversal key terminates its sleep mode and transmits its ID code. Onceout of range of the lock unit transmitter, the universal key returns tosleep mode.

In one embodiment, the lock unit reader searches for a universal key bitsequence including a pseudo random number jitter pattern and a specifiedbit sequence. The unlocking of the lock unit requires both a matchingjitter pattern between bits and the correct bit sequence. In addition,when two-way communication is available, a complex hash algorithmbetween universal key and receiver can be used as an encryption schemeto ensure that the universal key is genuine and to prevent unauthorizedcapture of the universal key ID code.

It is expected that in general use, the universal key battery is insleep mode eight (8) hours a day while the user is asleep. In addition,actual active use initiated by the motion detecting circuitry is aboutthree (3) hours out of a 24 hour day. However, this may vary from userto user depending on the activity of the user.

The always-on and constantly worn universal key has greatest utility forpeople whose lifestyle requires them to pass through many lockedstructures during an average day. For example, a computer servicetechnician who must pass through many locked doors to get to a securedcomputer server closet may have to pass through front security gates ofdifferent company facilities, then the garage gates of different garageareas, passing through secured lobby areas that require yet furtherkeying, to an appropriate elevator bank. Next, the technician travels toan appropriate floor in the office building and through an appropriatefront office door, followed by passage into more secured areas includingthe secured computer server closet. Conventionally, such a person wouldhave to carry many mechanical keys, electronic key cards, magnetic keycards, and/or remember various passcodes or PIN numbers. Such a userwould have to manually pull the appropriate card as he/she approachedeach and every secured locked structure. This can be time consuming andproblematic, especially if one of the multiple access keys is lost. Onthe other hand, with the systems described above, a single universal keycan be used to operate a plurality or all of the necessary securedaccess gateways. Each access gateway is programmed with a list ofpersonal identification numbers for persons who are authorized to passthrough that gateway, perhaps also indicating the direction of thepassage at given times during the day. If the universal key is lost andsecurity is notified, the old ID code can be immediately removed fromthe system and a new key issued with a completely differentidentification code, thus allowing the user to access all of theauthorized areas.

With the always-on and periodically transmitting key, a company may keeptrack of where specific key-carrying employees are throughout the day sothey can be contacted as required. This may be accomplished, forexample, by monitoring the access logs of each individual lock unit, orby placing monitoring units at strategic locations. Each of thesemonitoring units can continuously monitor the transmitting universalkeys that travel within the monitoring unit's range and communicate thisinformation to a central computer. The company can grant users access toas many different locked structures as deemed necessary but can alsocontrol time of day and days of the week that are allowed. For example,a company may require a night security guard to check various rooms andpass through secured door areas in a particular sequence and duringdifferent time intervals. The universal key allows this to happenwithout requiring the guard to have many different keys and will allowthe company to verify that the guard has indeed come within a certainrange of each of the doorways at appropriate times.

Embodiments of an access control system utilizing a universal key canhave numerous applications. In some embodiments, the ID code is used aspart of a tracking mechanism. For example, in a commercial setting, atimeclock system may incorporate a lock unit having a receiver forreceiving RF signals from universal keys possessed by employees who passwithin range of the timeclock. This tracking function may be provided inaddition to physically unlocking an access gateway (e.g., a door), ormay be provided alone without any door unlocking function (e.g.,employees exiting an establishment through a particular hallway willhave their exit time recorded by a timeclock receiver located in thehallway). This tracking function may also be used in conjunction with anemergency response system. In the event of an emergency, the emergencyresponse system may determine the locations of all employees bydetecting their universal key RF signals.

As described above, the lock unit may be used to actuate a lock on adoor in response to receiving an authorized ID code. This actuation canbe implemented using various mechanisms. In one embodiment, the doorlock comprises a lever latch-type door lock that is opened using asolenoid driven by an actuator after receiving an authorized ID code.This lever latch may also include a manual override lever on the insideand/or the outside of the door. In another embodiment, a locking pin isdriven via the solenoid into the lever latch after the door is closedand an alignment sensor detects that the lever latch is properly seated.This locking pin may provide the user with the equivalent of dead boltsecurity with a traditional lever lock system. In yet anotherembodiment, the lever latch system may comprise a manual overridebutton, enabling a user to disable the wireless unlocking mechanism andrequiring a physical key for entry. This may be desirable, when a userwill not be accessing the door for extended periods of time, e.g., whenthe user goes on vacation. In other embodiments, the lock may comprise apadlock or other mechanical latch.

In other embodiments, a universal key may be used as a useridentification mechanism for a payment system. One type of paymentsystem is a meter, such as a parking meter. This parking meter mayrecord when a particular universal key enters and exits a prescribedregion, e.g., a parking stall. This can be used to record the parkingtime for a particular user's car so that a time-based fee may becharged. In some embodiments, this payment mechanism may be incorporatedinto a parking meter that also includes other payment mechanisms, suchas a credit card-based or traditional coin-operated parking meter. Inthese embodiments, it may be desirable for the parking meter to includean indicator for indicating to a parking enforcement officer that auniversal key-based ID code is being charged for the automobilecurrently parked in the stall. This indicator may comprise, e.g., aflashing light or other display indicating that an RF signal having anID code is being received.

In another embodiment, the payment system is provided for authorizingpayment in exchange for other goods or services. For example, a user mayuse the universal key to authorize payment at a vending machine,laundromat, or any other equipment that accepts cash, ATM cards, creditcards, or other forms of payment. It may be desirable for the paymentsystem to provide some feedback to the user to indicate that a charge isbeing placed.

In another embodiment, the receiver may record a user's ID code as auser enters and exits a parking garage, thereby enabling the parkinggarage to charge the user for the time the user's vehicle was parked inthe garage. In some embodiments, the detection of the ID code may beused to open and close a garage door which prevents unauthorized usersfrom entering the garage. In other embodiments, the universal key isonly used to record entry and exit times, with no physical barriers(e.g., gate or garage door) being used for the garage. This may beuseful, e.g., in public parking garages.

In yet other embodiments, a utility control system may be controlledbased on the presence of universal keys in the building. This utilitycontrol system may, for example, activate or deactivate the HVAC(Heating, Ventilation, & Air Conditioning) and lighting within aparticular room or region of a building based on the presence of auniversal key. The utility control system may further customize theutility settings based on the particular universal key. For example, theutility control system may set the thermostat of a room to a particulartemperature corresponding to the ID code. The utility control system mayfurther control entertainment systems, such as audio or video systems,based on the ID code (e.g., turning the radio on to a user's favoritechannel when the ID code corresponding to that user is detected in theroom).

In yet other embodiments, the universal key may be used to control otherbuilding facilities, such as water, electricity, or gas flow. In oneembodiment, a hands-free sink may turn on the water in response todetecting a universal key within a prescribed distance and to turn thewater off once the universal key is no longer detected. This could helpto prevent overflow of a sink or bath and could also conserve water. Inanother embodiment, the universal key can be used to control electricityor gas flow to a cooktop stove. For example, after the stove is turnedon, the key carrier must remain within a prescribed distance of thestove, which contains a receiver circuit. If the user moves beyond thespecified distance, the electricity or gas flow is ceased. This may helpto prevent potential fire hazards caused by individuals forgetting toturn off the stove.

In yet other embodiments, the universal key may be used to activate ordeactivate a security alarm in a building. When an authorized ID code isdetected, the security alarm may deactivate, and when the ID code is nolonger detected, the security alarm may automatically arm.

The universal key can be used to assist in providing a facility designedto accommodate the requirements of the Americans with Disabilities Act.Currently, many buildings are equipped with buttons that activate motorsfor opening doors. In accordance with one embodiment, an ADA-compliantdoor may be equipped with a lock reader configured to open the doorautomatically in response to detecting the presence of a universal key.

The described universal key system may be implemented in variousembodiments as a method or apparatus using standard programming and/orengineering techniques to produce software, firmware, hardware, or anycombination thereof. The apparatus may comprise code or logicimplemented in hardware (e.g., an integrated circuit chip, ProgrammableGate Array (PGA), Application Specific Integrated Circuit (ASIC), etc.)or a computer readable medium, for example, magnetic storage medium(e.g. hard disk drives, floppy disks, tape), optical storage (e.g.,CD-ROMs, optical disks, etc.), volatile and non-volatile memory devices(e.g., EEPROMs, ROMs, PROMs, RAMs, DRAMs, SRAMs, firmware, programmablelogic, etc.). Code in the computer readable medium is accessed andexecuted by a processor. Of course, those skilled in the art willrecognize that many modifications may be made to this configurationwithout departing from the scope of the implementations.

While the invention has been described in terms of particularembodiments and illustrative figures, those of ordinary skill in the artwill recognize that the invention is not limited to the embodiments orfigures described. For example, various embodiments described aboverelate to the use of a lock unit to actuate a lock on a door, gate, orgarage upon receipt of an authorized ID code. In other embodiments, theuniversal key may be used to provide access to any type of securedportal, physical or electronic. A lock unit on a secured portal may beused to actuate any mechanism, e.g., electrical, mechanical, pneumatic,magnetic, or optical devices.

In addition, many of the embodiments described above comprise doors thatprovide one-way access control, i.e., an authorized ID code is needed topass through the door in one direction, but no key or code is requiredto pass through in the other direction. This arrangement is particularlysuitable for home security, where it is only desirable to prevent entry,not exit. In other embodiments, the access control system may providebidirectional access control. In other words, it may be desirable torequire that a user possess a universal key having an authorized ID codeto pass through a door or other gateway in either direction. It maystill be desirable to have a manual override (e.g., a mechanical keyinsertable into a tumbler lock) on one or both sides of the gateway.

In addition, a receiver or transmitter is described as a component ofthe various devices described herein. It will be understood that in someimplementations, the receiver and transmitter may be provided asseparate components, while in other implementations, the receiver andtransmitter functions may be provided by a single transceiver component.

The figures provided are merely representational and may not be drawn toscale. Certain proportions thereof may be exaggerated, while others maybe minimized. The figures are intended to illustrate variousimplementations of the invention that can be understood andappropriately carried out by those of ordinary skill in the art. Whilecertain embodiments of this invention have been described above, otherembodiments will be obvious in view of this description. This inventionshall only be limited by the claims and not by the above description.

1. An access control system, comprising: a key unit comprising anantenna and a transmitter configured to transmit a radio frequency (RF)signal over the antenna, the RF signal containing an identification (ID)code identifying the key unit; a plurality of lock units, each lock unitcomprising: an antenna for receiving the RF signal from the key unit;and a reader coupled to the antenna for receiving the RF signal from thekey unit, identifying the ID code contained in the RF signal, comparingthe received ID code with a list of one or more authorized ID codes, andif the received ID code is included in the list of authorized ID codes,granting access to a secured resource; wherein a first lock unit has afirst activation range and a second lock unit has a second activationrange different from the first activation range.
 2. The access controlsystem of claim 1, wherein each lock unit is adapted to receive the RFsignal from the key unit without line-of-sight access.
 3. The accesscontrol system of claim 1, wherein each lock unit has an activationrange for receiving the RF signal greater than 10 cm.
 4. The accesscontrol system of claim 1, wherein the first lock unit provides accessto a first type of portal and the second lock unit provides access to asecond type of portal different from the first type of portal.
 5. Theaccess control system of claim 1, wherein each lock unit is adapted toreceive the RF signal from the key unit with line-of-sight access. 6.The access control system of claim 1, wherein said granting access tothe secured resource comprises instructing an actuator to unlock amechanical locking mechanism.
 7. The access control system of claim 6,wherein said mechanical locking mechanism comprises a dead bolt, a leverlatch, or a padlock.
 8. The access control system of claim 6, whereinsaid mechanical locking mechanism comprises a lock on a physical portal.9. The access control system of claim 8, wherein at least one of thelock units further comprises an alignment sensor and the reader isconfigured to automatically close the lock on the portal after thealignment sensor senses that the portal has been closed and the key unitis beyond activation range.
 10. The access control system of claim 8,wherein said mechanical locking mechanism enables manual unlocking ofthe mechanical locking mechanism from the interior side of the portal.11. The access control system of claim 8, wherein said mechanicallocking mechanism unlocks the lock unit after receipt of an authorizedID code from the key unit positioned on an exterior side of the portal.12. The access control system of claim 8, wherein said mechanicallocking mechanism comprises a lever latch and a locking pin for lockingthe lever latch, said locking pin being actuated by a solenoid after theportal is closed and an alignment sensor indicates that the lever latchis properly seated.
 13. The access control system of claim 8, whereinsaid mechanical locking mechanism comprises an override button fordisabling the reader.
 14. The access control system of claim 8, whereinsaid mechanical locking mechanism comprises a keyhole for receiving aphysical key to unlock the lock unit.
 15. The access control system ofclaim 1, wherein the antenna of the key unit has a meandering shape. 16.The access control system of claim 1, wherein said granting access tothe secured resource comprises granting access to an electronic system.17. The access control system of claim 1, wherein said key unittransmits the ID code on a periodic basis.
 18. The access control systemof claim 1, wherein said key unit comprises a motion detector, said keyunit having a sleep mode during which the key unit does not transmit theID code and an active mode during which the key unit transmits the IDcode on a periodic basis, wherein the key unit enters the sleep modewhen no motion is detected for a predetermined period of time and thekey unit enters the active mode when motion is detected.
 19. The accesscontrol system of claim 1, wherein the key unit further comprises anon/off switch.
 20. The access control system of claim 1, wherein the keyunit further comprises a battery and a visual or audible batteryindicator for indicating a status of the battery.
 21. The access controlsystem of claim 1, wherein said key unit further comprises a battery andan on/off switch, said on/off switch configured to disengage the batterywhen in an off state and connect the battery when in an on state. 22.The access control system of claim 21, wherein the on/off switchcomprises a rotatable battery compartment cover such that the on/offswitch is in the off state when the battery compartment cover ispartially rotated and is in the on state when the battery compartmentcover is fully rotated.
 23. The access control system of claim 1,wherein the key unit further comprises a battery and an on/off switch,said on/off switch comprising a reed-relay and a positionable magnet.24. The access control system of claim 1, wherein said key unitcomprises: a primary battery for powering the transmitter to transmitthe RF signal; and a secondary battery for powering an alarm configuredto activate when the primary battery reaches a predetermined minimumcharge.
 25. The access control system of claim 1, wherein said key unitis enclosed within a metal housing, and wherein said antenna is providedon an exterior of the metal housing.
 26. The access control system ofclaim 1, wherein the key unit further comprises a receiver and at leastone of the lock units includes a reader having a transmitter.
 27. Theaccess control system of claim 26, wherein the transmitter is configuredto encrypt the ID code in the transmitted RF signal.
 28. The accesscontrol system of claim 26, wherein: at least one of the lock units isconfigured to transmit an interrogation signal; and the key unit has asleep mode during which the key unit does not transmit the ID code andan active mode during which the key unit transmits the ID code on aperiodic basis, wherein the key unit enters the active mode upon receiptof the interrogation signal.
 29. The access control system of claim 1,wherein at least one of the lock units is configured to respond to RFsignals in a directionally preferential basis.
 30. The access controlsystem of claim 1, wherein at least one of the lock units is configuredto only open in response to RF signals received from a first side of adoor.
 31. The access control system of claim 29, wherein the lock unitconfigured to respond to RF signals in the directionally preferred basiscomprises an RF signal shield positioned on one side of the antenna. 32.(canceled)
 33. The access control system of claim 30, wherein at leastone of the lock units comprises a first antenna provided on a first sideand a second antenna on a second side and is configured to compare asignal strength received by the first antenna with a signal strengthreceived by the second antenna to determine the location of the keyunit.
 34. The access control system of claim 1, wherein at least one ofthe lock units is configured to only respond to RF signals when the keyunit is a predetermined distance from the lock unit.
 35. The accesscontrol system of claim 1, wherein the reader further comprises aprogrammable microcontroller.
 36. The access control system of claim 35,wherein the reader further comprises a communications interface coupledto the microcontroller.
 37. The access control system of claim 36,wherein the microcontroller is configured to receive updates to the listof authorized ID codes via the communications interface.
 38. The accesscontrol system of claim 36, wherein the communications interfacecomprises a modem, a network port, or a wireless communications adapter.39. The access control system of claim 36, wherein the communicationsinterface comprises a wireless communications adapter compliant withIEEE 802.11, IEEE 802.16, or Bluetooth.
 40. The access control system ofclaim 1, wherein the reader is configured to grant access to the securedresource if the received ID code is included in the list of authorizedID codes during a predetermined access time period.
 41. The accesscontrol system of claim 1, wherein the reader of at least one of thelock units is configured to grant access to the secured resource only ifa plurality of authorized ID codes are simultaneously received.
 42. Theaccess control system of claim 1, wherein at least one of the lock unitsfurther comprises a memory, wherein the reader is configured to storeinformation regarding ID codes received from key units in the memory.43. The access control system of claim 42, wherein at least one of thelock units is provided in an automobile parking garage and the reader isconfigured to store information regarding time of entry and exit of eachkey unit into the automobile parking garage.
 44. The access controlsystem of claim 1, further comprising a meter comprising: a meterantenna; and a meter reader coupled to the meter antenna for receivingthe RF signal from the key unit and for storing information regarding alength of time the key unit is within operational range of the meter.45. The access control system of claim 44, wherein the meter furthercomprises an indicator for indicating that the RF signal is beingreceived from the key unit.
 46. The access control system of claim 1,further comprising: a business machine coupled to one of the pluralityof lock units, wherein said granting access to the secured resourcecomprises granting operational access to the business machine.
 47. Theaccess control system of claim 1, further comprising: an elevatorcontroller coupled to one of the plurality of lock units, wherein saidgranting access to the secured resource comprises calling an elevator toa location of the received ID code.
 48. The access control system ofclaim 47, further comprising: wherein the lock unit coupled to theelevator controller further comprises a memory for storing default floorpreferences corresponding to each ID code, wherein the lock unit isconfigured to transmit a destination floor to the elevator controllerbased on the ID code.
 49. The access control system of claim 1, furthercomprising: a building utility control system coupled to one of the lockunits positioned in a room, wherein the building utility control systemdeactivates a utility service in the room when an ID code is not beingreceived by the lock unit.
 50. The access control system of claim 1,further comprising an alarm system coupled to one of the lock units, thealarm system configured to deactivate when an authorized ID code isreceived or activate when an authorized ID code is not being received.51. The access control system of claim 1, further comprising a paymentsystem coupled to one of the lock units, the payment system configuredto record an ID code as payment for a service or product.
 52. The accesscontrol system of claim 1, further comprising a water valve controlsystem coupled to one of the lock units, the water valve control systembeing configured to shut off a water valve if an authorized key unit isnot detected within a predetermined range.
 53. The access control systemof claim 1, further comprising a kitchen appliance control systemcoupled to one of the lock units, the kitchen appliance control systembeing configured to deactivate a kitchen appliance if an authorized keyunit is not detected within a predetermined range.
 54. The accesscontrol system of claim 1, further comprising an automation controlsystem coupled to one of the lock units, the automation control systembeing configured to activate one or more devices to a predeterminedsetting based on the received ID code.
 55. The access control system ofclaim 54, wherein the one or more devices comprise a light, an HVACsystem, a video device, or an audio device.
 56. The access controlsystem of claim 1, wherein said key unit is hands-free and transmits theRF signal omnidirectionally.
 57. The access control system of claim 1,wherein said key unit comprises a water-resistant and shock-resistantkey fob.
 58. The access control system of claim 1, wherein said readeris configured to provide an audible or visible indication that the lockunit has locked.
 59. The access control system of claim 1, furthercomprising a plurality of tracking readers configured to monitor keyunits that pass within an operational range of the tracking reader.60-63. (canceled)
 64. A method of providing access control, comprising:carrying a key unit configured to transmit a radio frequency (RF) signalcontaining an identification (ID) code identifying the key unit; andbringing the key unit within an activation range of a plurality ofsecured portals such that at each secured portal, a lock unit in thesecured portal identifies the ID code contained in the RF signal,compares the received ID code with a list of one or more authorized IDcodes, and if the received ID code is included in the list of authorizedID codes, grants access to a secured resource, wherein a first securedportal has a first activation range and a second secured portal has asecond activation range different from the first activation range. 65.The access control system of claim 59, wherein the tracking readers areconnected to a timeclock system that records when an employee passesthrough a location.
 66. The access control system of claim 59, whereinthe access control system is part of an emergency response system whichcan determine the locations of all employees by detecting theiruniversal key RF signals.
 67. The access control system of claim 1,wherein at least one of the plurality of lock units is provided in anautomobile.